This is the 14762nd most frequent Korean word.
바뀌었는데
"It changed" or "was changed."
In this sentence, '바뀌었는데' refers to the sudden change in the weather, which is part of the cause-effect relationship expressed here.
날씨가 갑자기 바뀌었는데 너무 추워졌어요.
The weather suddenly changed, and it became very cold.
Here, '바뀌었는데' discusses the change in the meeting time, which prompts a following question about adjustments.
약속 시간이 바뀌었는데 맞춰서 올 수 있겠어요?
The meeting time changed; can you make it accordingly?
In this context, '바뀌었는데' addresses the alteration of rules, followed by a request for clarification.